Marlys J. Harris also answers your financial questions on Cable News Network’s Your Money every Saturday at 3:30 p.m. eastern time and Sunday at 9:30 a.m. Send your question, name, address and phone number to Money Helps, Time & Life Building, Rockefeller Center, New York, N.Y. 10020.

► Q. I have been offered an opportunity to purchase $10,000 worth of silver or gold, which would be sold to a guaranteed buyer 10 years later. The brokerage, Morgan Bradford & Co. of Los Angeles, talks of a 15% annual return. Does this sound good?

– Frederick Muller, Hudson, N. K

A. It sounds great — until you find out who you are really dealing with. Morgan Bradford is just a telemarketer for the Zurich-based Eurogold Exchange, whose assets were temporarily frozen in January after federal and California officials complained that the company was offering options illegally. The case against Eurogold is strictly a civil suit at this point. But the man officials say was its head — Gerald L. Rogers — had been convicted in 1987 of mail and tax fraud after an earlier investment scheme. Rogers, also known as J.K. Glenn, jumped bail that time by fleeing the country (U.S. marshals say he may have sailed away on his 10 i -foot yacht, the Laissez-Faire). But he was arrested in Switzerland in January and hauled back to L.A. Meanwhile, Morgan Bradford says it knew nothing of any Eurogold improprieties and remains in business selling different investments. But even without these juicy details (such as the prosecution calling Rogers “an evil, misanthropic sociopath“ in a 1987 sentencing memorandum), you were smart to hold on to your wallet. Look at the sales literature you received: it promises a return of “up to” 15% on the silver, which could just as well mean 0%. It also predicts that “fortunes will be made in silver as prices soar to 81,000 an ounce in the year 2000!” — quite a stretch from its current $5-an-ounce level. All in all, this deal was literally too good to be true.

Q.  I bought a condominium time-share for $3,480 in 1986 at Holly Lake Ranch in Hawkins, Texas. It was easy to visit during our designated week when my family and I lived in Dallas, but we have since moved. I don’t mind making the mortgage payments, but is there any way that I can get out of paying the $35-a-month maintenance fee?

– Brad Sigley, Cherry Hill, N.J.

A. Sorry. The sales document you signed leaves you no room to wriggle out of the fee. Worse, the management company can raise the fee by up to 10% a year; it can even hit you with “special assessments” in the event that, say, the pool becomes infested with slimy, gooey things. Of course, one way out of the fees is to sell your time-share. But let me tell you, Brad, it’s a jungle out there. Some unscrupulous resale brokers charge a nonrefundable $300 to $500 to list your property and then skip town. And if you’re looking for buyers, the undergrowth thickens. Vaco Vacation Concepts (5401 Kirkman Rd., Suite 730, Orlando, Fla. 32819; 800-445-8226), a large and reputable broker, reports that it sells only 10% to 15% of its listings. The price may be as little as half what you paid, minus a commission of up to 35%. To get some use out of your investment, you might join a time-share exchange program. The largest is Resort Condominiums International (3502 Woodview Trace, Indianapolis, Ind. 46268; 800-338-7777), which arranged 665,497 exchanges last year. But this service is not free either. There’s a $200 initiation fee (which Holly Lake will consider paying for you) plus a $59-a-year membership fee and $84 a week for each domestic exchange. If you ever get an urge to sink money in a time-share again, fill the tub and get in. That might remind you of the bath you’re taking in Holly Lake.

Q. In March 1989, I wrote a check for $5,000 from a credit union account in Alexandria. Va. to a bank for a certificate of deposit. The bank, Warren Five Cents Savings Bank in Peabody, Mass., claims that it was paid by the Federal Reserve. but the check has never cleared the credit union. I have called both institutions, but neither has taken action. What can I do?

– Randolph Fix, Beverly, Mass.

A. Where were you when Diogenes was looking for an honest man? But at least the troublesome $5,000 will soon be off your hands. After several calls, a Warren Five spokesperson acknowledged that the mix-up occurred at Warren Five’s end. Although the bank opened your CD promptly last March, your check—for some unknown reason—never made it through the Federal Reserve. Why didn’t the bank figure this out when you alerted it to the problem months ago? The bank points to a major office move and a computer conversion, which may have resulted in your problem being overlooked. On the bright side, the bank will keep your CD open and will allow you to retain the interest. Simply stop payment on the original $5,000 check (Warren Five will pick up the fee for that too), and then write out a new check for the bank.

► Q. I noticed that the Vanguard Group deposited my $1,500 check in its bank Aug. 18. but the funds were not credited to my money-market mutual fund account until Aug. 21. Does Vanguard make money on our cash by using it for a few days before crediting customers, thus profiting on the “float!” Is this another hidden cost of these funds?

– John A. Schmidt, Camp Hill, Pa.

A. Vanguard did nothing wrong. Investment companies wait until the next business day to credit deposits to customers’ money-market accounts: the practice is not a deep, dark conspiracy. In fact, it is spelled out in the prospectus — though in language you might understandably have slept through. Money funds need to allow a business day to convert your check to usable federal funds. Aug. 18 was a Friday. so your money went in on the next business day. Monday. Aug. 21.

► Q. I have a 1988 $10 bill that was printed only on one side. Does it have any value as a collectible, and if so, where can I sell it?

– Lorry Lin, Woodside, N. Y.

A. The Federal Reserve, in its infinite generosity. would give you a big $10 for your $10 bill, so forget that. Genuine currency with errors does have collectible value, however, although the worth of a misprinted bill depends on which side is blank. All bills go through three separate printings — first the back; then the face design on the front, including the denomination and (for a $ 10 bill) the face of Alexander Hamilton; and finally the seals and serial numbers on the front. Blank-backed bills are the most common; they can be worth up to $ 125 for a crisp, clean ten-spot. If the seals and serial numbers are missing, the note may sell for $100 to $150. And if the face design is missing, you’ve hit the jackpot: your currency misfit could be worth $250 to $300. Nobody knows how many of the 6 billion bills printed each year contain such errors. But Harry E. Jones, one of the nation’s largest error-note dealers, estimates that he has handled no more than 300 of the garden-variety blank-tacked ones in his 25-year career. To sell yours, try a local coin dealer or Jones’ Rare Coins & Currency (P.O. Box 30369. Cleveland. Ohio 44130:216-884-0701).